河图雷达武汉东湖表面波浪探测实验

River discharge are very important for hydraulic engineering design and hydrology -water resources management. Traditional discharge measurement approaches based on stage-discharge curve require rating or calibration before used, whose applications are limited by flow patterns, climate and other external conditions.As river velocity is the crucial parameter of discharge,to solve the difficult problem of the flow measurement, this paper proposed that the surface velocity distribution of river channel cross-section can be remote sensed by a full-digital coherent Doppler radar system named "HeTu", combination of the river depth and discharge is then calculated by velocity area method which does not require pre-calibration. A field experiment was conducted at Wuhan East-lake, and the radar echoes indicated that HeTu can measurement the surface water velocity using resonant Bragg scattering from water waves and the mobile passenger ship. The Bragg echoes with Signal-to-Noise Ratios(SNR) over 40dB were obtained from both water waves and ships, and the maximum range was over 500m, which proved that the HeTu radar system can work effectively.